Reg Environ Change (2014) 14:157–166 DOI 10.1007/s10113-013-0475-x ORIGINAL ARTICLE Analysis of deforestation patterns in the central Menabe, Madagascar, between 1973 and 2010 Dietmar Zinner • Christian Wygoda • Leon Razafimanantsoa • Rodin Rasoloarison • Herizo T. Andrianandrasana • Jo¨rg U. Ganzhorn • Frank Torkler Received: 17 September 2012 / Accepted: 3 May 2013 / Published online: 24 May 2013 Ó The Author(s) 2013. This article is published with open access at Springerlink.com Abstract The central Menabe region still holds the largest Keywords Madagascar Á Deforestation Á Dry forest Á remnant of dry forest in western Madagascar. These forests Satellite image time series Á Remote sensing Á Political are home to high floral and faunal diversity including a crisis number of local and regional endemics. The forests of the central Menabe have been classified as conservation hot- spots. However, pressure on these forests is strong and Introduction deforestation continues on a large scale. To quantify recent forest loss, we used a series of satellite images (1973–2010) Madagascar, the world’s fourth largest island of approxi- for estimating annual deforestation rates. The overall rate mately 587,000 km2, is located off the south-eastern coast was 0.67 %, but it accelerated during certain periods to over of Africa. It is regarded as one of the major biodiversity 1.5 % with a maximum of 2.55 % per year between 2008 hotspots (Myers et al. 2000), because it harbours excep- and 2010. Not all areas within the forest block of the central tional biota with high overall diversity and levels of Menabe are affected similarly. Areas surrounding existing endemism (Goodman and Benstead 2005). At the same clearings show the highest losses of largely undisturbed time, its plant and animal species are among the most forest. If deforestation continues at the same rate as during endangered (Mittermeier et al. 2004; IUCN 2011). As in the last years, 50 % of the 1973 forest cover will be gone other parts of the tropics, habitat loss and fragmentation are within the next 11–37 years. among the most pervasive causes of biodiversity loss (Laurance et al. 2000; Geist and Lambin 2002; Fahrig 2003; Gardner et al. 2010; Irwin et al. 2010). The vast D. Zinner (&) majority of the terrestrial biota is forest dependent, but Cognitive Ethology Laboratory, Deutsches Primatenzentrum, deforestation has reached alarming proportions. Although Go¨ttingen, Germany e-mail: [email protected] historical estimates of national forest cover of Madagascar are difficult and somehow controversial (e.g. Dufils 2003), C. Wygoda Á F. Torkler the tendency of forest loss is obvious. Dufils (2003) Landscape Management and Nature Conservation, Hochschule reported deforestation rates for evergreen forest formations fu¨r nachhaltige Entwicklung Eberswalde (FH), Eberswalde, Germany of 102,000 ha per year in the period from 1950 to 1999. These estimates are similar to those of Green and Sussman L. Razafimanantsoa Á R. Rasoloarison (1990) for the eastern rain forests which had lost 50 % Behavioral Ecology and Sociobiology Unit, Deutsches between 1950 and 1985 with a rate of 111,000 ha per year. Primatenzentrum, Go¨ttingen, Germany Monitoring and analysing deforestation in Madagascar H. T. Andrianandrasana was focussed on the eastern humid forests (Green and Durrell Wildlife Conservation Trust, Antananarivo, Madagascar Sussman 1990; Nelson and Horning 1993; Dufils 2003; Bollen and Donati 2006;Va˚gen 2006). However, defor- J. U. Ganzhorn Biozentrum Grindel, Zoologisches Institut, estation rates in the western dry deciduous forests with Universita¨t Hamburg, Hamburg, Germany their comparable levels of endemism and biodiversity were 123 158 D. Zinner et al. similarly high or even higher (Smith 1997; Whitmore 2008); the only population of Madame Berthe’s mouse 2000; Harper et al. 2007; Scales 2011). It was estimated lemur (Microcebus berthae), the smallest primate of the that over 97 % of Madagascar’s dry deciduous forests had world (Rasoloarison et al. 2000; Yoder et al. 2000); the flat- already disappeared by the year 2000 (WWF 2001) and tailed tortoise (Pyxis planicauda; Tidd et al. 2001); and a with them unique aspects of Malagasy biodiversity frog (Aglyptodactylus laticeps; Glaw et al. 1998; Glos et al. (Whitmore and Sayer 1992; Ganzhorn et al. 2001; Allnutt 2008). Sixteen other vertebrate species with extremely et al. 2008). This matches the situation of most tropical dry restricted ranges are found in the KAFC including the forests that have been neglected due to an emphasis on striped mongoose (Mungotictis decemlineata; Raz- humid tropical forests (Janzen 1988; Lerdau et al. 1991; afimanantsoa 2003) and the white-breasted mesite (Mesi- Bellefontaine et al. 1997). tornis variegata; Durbin et al. 2005; reviewed by Goodman Causes for forest removal in Madagascar vary regionally and Raselimanana 2008). Tree species diversity is notably (Gorenflo et al. 2011). However, the main direct cause of high with more than 200 species (Abraham et al. 1996; forest loss in western Madagascar is deforestation through Rakotonirina 1996). Current pressures in the region stem intentional burning to clear land for agriculture, locally primarily from an expanding human population which uses known as hatsake, either for subsistence or for the market slash-and-burn agriculture (for subsistence and cash crop), production (Scales 2011, 2012). With an expanding rural legal and illegal selective logging and animal trapping for population and increasing degradation of existing arable subsistence. There have been only five legal timber har- lands, the pressure on the remaining forest is extremely vesters in the region, four of which held harvesting lots high. Selective logging poses additional threats to forest defined by the service of Environment and Forests in the habitats (Whitehurst et al. 2009). Central Menabe region; all other activity was considered A priority-setting workshop concerning Madagascar in illegal. For instance, during the monitoring of the north- 1995 identified several sites of the dry deciduous forest eastern corner of the Kirindy Forest in 2002, the Waters and ecosystem in need of immediate biodiversity protection, Forests service seized 400 logs and destroyed 40 lemur traps. among them were the southern and the central Menabe In order to insure the survival of the endemic species and to regions (Ganzhorn et al. 1997; Hannah et al. 1998). In protect their habitat, an initiative was launched to improve 1997, a large contiguous block of the dry forest in the the legal protection of the KAFC and to create a protected southern Menabe became legally protected as the Kirindy- area, called ‘Aire Prote´ge´e Menabe Antimena’ (Ministe`re de Mitea National Park, one of the first national parks in the l’Environnement, des Eaux et Foreˆts 2006). western forest zone (De´cret no 97-1453, 18 December To further support the process towards creating a per- 1997 by the Ministe`re de l’Environnement, des Eaux et manent protected area in the central Menabe and to identify Foreˆts). The central Menabe region includes the area deforestation hotspots within the region, we performed a between the Morondava River in the south and the Tsiri- temporal and spatial analysis of forest loss in KAFC for the bihina River in the north. The northern part of the region, last 37 years (1973–2010) with special interest in the between Tomitsy and Tsiribihina rivers, still contains one deforestation rates during years of civil unrest, such as of the largest tracts of dry deciduous forests left in Mad- during the transition between the presidents Rasiraka and agascar, the Kirindy-Ambadira Forest Complex (KAFC). Ravalomanana from 2001/2002 and after Madagascar’s Prior to the establishment of Kirindy-Mitea National Park, unconstitutional change in government in 2009. the only protected area within the region was the Special Reserve Andranomena (approx. 7,000 ha), which is located south of the KAFC and south of the Tomitsy River. Study area However, it has already lost most of the local endemics because of forest degradation (Smith et al. 1997; Ganzhorn The study area is located in the dry deciduous forest of and Schmid 1998; Tidd et al. 2001). coastal western Madagascar between the Tomitsy The central Menabe has experienced a long history of (44°350E, 20°080S) and the Tsiribihina rivers (44°370E, forest conversion into agriculture, both for plantations and 19°440S) (Fig. 1). The Kirindy Forest constitutes the subsistence (Scales 2011), and further conversion of the southern part and the Ambadira Forest the northern part of remaining forests in the central Menabe poses serious threats the KAFC. In the west, the KAFC adjoins the coastal dunes to the survival of several endemic vertebrates. The global and marshes, and in the east, the forest borders savannah distribution of four vertebrate species is restricted to the grassland. The climate is characterized by pronounced forested areas between the Morondava and Tsiribihina riv- seasonality with little or no rain from April to November, ers, with the last remaining population of the giant jumping followed by a rainy season from December to March rat (Hypogeomys antimena), the largest living endemic (Ganzhorn 1995a; Sorg and Rohner 1996). The mean rodent of Madagascar (Sommer et al. 2002; Young et al. annual precipitation between 1906 and 1993 was 767 mm/year 123 Analysis of deforestation patterns 159 Fig. 1 Map of Madagascar showing the geographical position of the study area and the Kirindy-Ambadira